Mid-infrared frequency comb with 25 pJ threshold via CW-seeded optical parametric generation in nonlinear waveguide

TL;DR

This paper reports a highly efficient, low-threshold mid-infrared frequency comb generation using CW-seeded optical parametric processes in nonlinear waveguides, with exceptionally low noise and broad bandwidth capabilities.

Contribution

It introduces a novel mid-infrared comb source with 74% conversion efficiency and a 25 pJ threshold, significantly lower than bulk methods, enabled by nonlinear waveguides and broadband pumping.

Findings

Conversion efficiency of 74% achieved.

Threshold of 25 pJ demonstrated, over 300 times lower than bulk systems.

Mid-infrared comb exhibits extremely low relative intensity noise.

Abstract

We demonstrate efficient generation of mid-infrared frequency combs based on continuous-wave-seeded femtosecond optical parametric generation in nonlinear waveguides. Conversion of the near-infrared pump to signal and idler light takes place with very high efficiency (74 %) and the threshold (25 pJ) is over 300 times lower than in bulk analogs. Relative intensity noise of the mid-infrared comb is exceptionally low, below 5*10-5 (detector-limited, integrated from 10 Hz to 2 MHz). Furthermore, the mid-infrared bandwidth can be increased by driving the process with broadband pump obtained via supercontinuum generation.